chore(security,refactor): extract sanitization and improve code quality (#41)

* chore(security,refactor): extract sanitization and improve code quality

- [x] Extract sanitization functions to dedicated sanitization.go module
- [x] Add comprehensive golangci-lint v2 configuration with security rules
- [x] Replace interface{} with any type throughout codebase
- [x] Add admin API authentication security warning
- [x] Extract WebSocket and stats streaming constants
- [x] Add best-effort error handling comments for resource cleanup
- [x] Expand sensitive field patterns for improved PII redaction
- [x] Simplify safety checks and remove redundant nil validations
- [x] Improve test coverage for password field redaction patterns

* refactor: replace interface{} with any type alias

- [x] Replace all `map[string]interface{}` with `map[string]any`
- [x] Replace all `interface{}` with `any` in function signatures and type definitions
- [x] Update sync.Pool New function returns from `interface{}` to `any`
- [x] Add package documentation comments to 8 package files
- [x] Update type assertions and casts to work with `any` type

cache/memory/lru_memory_cache.go

@@ -38,12 +38,12 @@ func NewLRUMemoryCache(maxMemorySize, maxEntries int64) *LRUMemoryCache {
 		entries:       make(map[string]*lruEntry),
 		evictList:     list.New(),
 		gzipWriterPool: &sync.Pool{
-			New: func() interface{} {
+			New: func() any {
 				return gzip.NewWriter(nil)
 			},
 		},
 		gzipReaderPool: &sync.Pool{
-			New: func() interface{} {
+			New: func() any {
 				return &gzip.Reader{}
 			},
 		},
@@ -257,11 +257,11 @@ func (c *LRUMemoryCache) decompress(data []byte) ([]byte, error) {
 }
 
 // GetStats returns cache statistics
-func (c *LRUMemoryCache) GetStats() map[string]interface{} {
+func (c *LRUMemoryCache) GetStats() map[string]any {
 	c.mu.RLock()
 	defer c.mu.RUnlock()
 
-	return map[string]interface{}{
+	return map[string]any{
 		"entries":      atomic.LoadInt64(&c.currentCount),
 		"memory_bytes": atomic.LoadInt64(&c.currentMemory),
 		"max_entries":  c.maxEntries,